Can eddies make ocean deserts bloom?
Can eddies make ocean deserts bloom?
An eddy-resolving coupled ecosystem-circulation model of the North Atlantic is used to investigate the impact of mesoscale variability on the nitrate supply to the light-lit euphotic zone. The focus is on the oligotrophic subtropical gyre where eddies have been suggested to reconcile apparently contradictory observational estimates of nutrient supply and export production. Comparison with observations indicates that the numerical model provides a realistic description of the subtropical eddy field and its interaction with biogeochemical tracers. The model results illustrate that the eddy-induced nitrate flux into the euphotic zone is largest near the margins of the oligotrophic gyre where both vertical and lateral nutrient supply by eddies are effective. Typical values of simulated eddy-induced nitrate supply are 0.05 mol m?2 yr?1, which is much lower than has been suggested previously. This new estimate of eddy-induced nitrate supply is not sufficient to reconcile seemingly contradictory observational estimates of biological production in the subtropics. Alternative sources of fixed nitrogen, deviations from standard elemental stoichiometry, and possible effects of interannual variability will have to be considered in order to resolve apparent observational discrepancies in the oligotrophic subtropical gyres.
1-8
Oschlies, Andreas
75e18f55-3134-44a2-82ba-71334397727f
2002
Oschlies, Andreas
75e18f55-3134-44a2-82ba-71334397727f
Oschlies, Andreas
(2002)
Can eddies make ocean deserts bloom?
Global Biogeochemical Cycles, 16 (4), .
(doi:10.1029/2001GB001830).
Abstract
An eddy-resolving coupled ecosystem-circulation model of the North Atlantic is used to investigate the impact of mesoscale variability on the nitrate supply to the light-lit euphotic zone. The focus is on the oligotrophic subtropical gyre where eddies have been suggested to reconcile apparently contradictory observational estimates of nutrient supply and export production. Comparison with observations indicates that the numerical model provides a realistic description of the subtropical eddy field and its interaction with biogeochemical tracers. The model results illustrate that the eddy-induced nitrate flux into the euphotic zone is largest near the margins of the oligotrophic gyre where both vertical and lateral nutrient supply by eddies are effective. Typical values of simulated eddy-induced nitrate supply are 0.05 mol m?2 yr?1, which is much lower than has been suggested previously. This new estimate of eddy-induced nitrate supply is not sufficient to reconcile seemingly contradictory observational estimates of biological production in the subtropics. Alternative sources of fixed nitrogen, deviations from standard elemental stoichiometry, and possible effects of interannual variability will have to be considered in order to resolve apparent observational discrepancies in the oligotrophic subtropical gyres.
This record has no associated files available for download.
More information
Published date: 2002
Identifiers
Local EPrints ID: 12722
URI: http://eprints.soton.ac.uk/id/eprint/12722
ISSN: 0886-6236
PURE UUID: d3d3984e-fd46-4abf-91c8-d52ba242671f
Catalogue record
Date deposited: 02 Dec 2004
Last modified: 15 Mar 2024 05:07
Export record
Altmetrics
Contributors
Author:
Andreas Oschlies
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics